Rotary packaging machines

ABSTRACT

A rotary packaging machine  10  having rotatably driven stripper bars  17  and  18  that strip tubular bag material  36  prior to sealing of the bags being formed. To further inhibit material being located between the sealing jaws there is provided tube closer bars  28  and  29 . The bar  28  has a longitudinally extending projection  34  that is received within a longitudinally extending recess  35  of the bar  29 . The tubular bag material  36  by engagement within the recess  35  by the projection  34  laterally projects the bag material  36  and three longitudinally spaced locations  54.

TECHNICAL FIELD

[0001] The present invention relates to rotary packaging machines andmore particularly but not exclusively to rotary packaging machines usedto package snack foods.

BACKGROUND OF THE INVENTION

[0002] Disclosed in U.S. Pat. No. 4,663,917 is a rotary packagingmachine The machine includes a pair of sealing jaws that are rotatablydriven about parallel spaced generally horizontal axes. Associated withthe jaws are stripper members which strip the bag material to inhibitproduct being located between the sealing jaws. Also associated with thesealing jaws are closer bars that engage the tubular bag material toagain inhibit product being located between the jaws.

[0003] As the sealing jaws engage the tubular bag material they aregenerally travelling at the same speed as the bag material. Howeversince the jaws are corrugated the bag material upstream of the jaws isaccelerated. This in turn causes the bag material to move between thecloser bars to the extent that the bag material initially above thecloser bars passes through the closer bars to be located immediatelybelow the closer bars just prior to scaling. This can result in productabove the closer bars, particularly in the case of snack foods wherethere are crumbs, being pulled past the closer bars. This in turn canresult in the location of product, such as crumbs, in the area betweenthe sealing jaws. This results in an inferior seal and frequently in thebag material being punctured.

[0004] Previous packaging machines are described in patentspecifications US20020092271, U.S. Pat. No. 6,367,230, U.S. Pat. No.6,189,301, U.S. Pat. No. 6,052,971, U.S. Pat. No. 6,006,503, U.S. Pat.No. 5,881,539, U.S. Pat. No. 5,622,033, U.S. Pat. No. 5,622,032, U.S.Pat. No. 5,463,851, U.S. Pat. No. 4,999,974, U.S. Pat. No. 4,947,618,U.S. Pat. No. 4,759,170, U.S. Pat. No. 4,663,917, U.S. Pat. No.4,566,253, U.S. Pat. No. 4,563,862, U.S. Pat. No. 4,532,753, U.S. Pat.No. 4,391,081, U.S. Pat. No. 3,849,965, JP11180401, JP8040403,JP07132907.

[0005] In respect of U.S. Pat. No. 6,052,971 there is described thereina packaging machine provided with “wiper means” in the form ofoverlapping engagement portions that strip the bag material and causethe bag material to move upwardly relative to the sealing jaws. U.S.Pat. No. 4,566,253 describes a packaging machine that includes a seriesof interacting rollers that move the bag material upwardly to therebystrip the bag material by causing the bag material to move between apair of stripping jaws. The interacting rollers reciprocate lineally ina direction generally transverse of the bag material. U.S. Pat. No.6,189,301 describes a packaging machine having squeezing bars that arecaused to oscillate angularly through approximately 45° to engage thebag material to inhibit product passing through the bag material andbeing engaged by the sealing jaws. The squeezing bars are mountedseparately to the sealing jaws and do not rotate therewith.

[0006] The machines described in the above identified patentspecifications do not overcome the above described problem.

OBJECT OF THE INVENTION

[0007] It is the object of the present invention to overcome orsubstantially ameliorate the above disadvantage.

SUMMARY OF THE INVENTION

[0008] There is disclosed herein a rotary packaging machine including:

[0009] a pair of rotatably driven jaws to engage tubular bag materialpassing through the machine in a general direction of travel, the jawsbeing adapted to form transverse seals in the bag material to formdiscrete bags containing product;

[0010] a drive member supporting each jaw, the drive members beingdriven in synchronism in opposite rotational directions; and

[0011] an assembly to at least substantially prevent product beinglocated between the jaws during sealing engagement with the tubular bagmaterial, said assembly having a first operative configuration allowingproduct to pass along the bag material and a second operativeconfiguration, said assembly when in said second configuration beingengaged with the bag material to at least substantially prevent productbeing located between the jaws during sealing, said assembly includingbag material deflecting and closing members mounted on said drive memberso as to rotate therewith, which deflecting and closing members closesaid bag material and deflect said bag material laterally relative tosaid direction to at least substantially prevent product being locatedbetween tie jaws when forming said seals.

[0012] Preferably, said deflecting and closing members include:

[0013] a pair of bar members which deflect and close said tubular bagmaterial, a deflector bracket for each bar member, each bracket mountingthe associated one of the bar members on a respective one of the drivemembers, and wherein the brackets provide for relative movement betweeneach bar member and the jaw of the respective drive member so that eachbar member moves relative to its associated jaw when the bar member isengaged with the tubular bag material.

[0014] Preferably, the bar members deflect the tubular bag materiallaterally in one direction and laterally in the opposite direction tosaid one direction.

[0015] Preferably, the bar members are configured to also close the bagmaterial; and said machine further includes strippers that engage thebag material downstream of the s bar members in said direction to stripthe bag material prior to sealing, said strippers being mounted on thedrive members so that each drive member has mounted on it one of the barmembers and one of the strippers.

[0016] Preferably, each detector bracket is pivotally mounted on itsrespective drive member so that the bar member moves angularly relativeto the respective one of the drive members, and said machine furtherincludes a pair of stripper brackets that support the strippers, eachstripper bracket being plurality mounted on a respective one of thedrive members so that the strippers move angularly relative to theirrespective drive members.

[0017] Preferably, the machine further includes first springs urging thebar members to a predetermined position from which the bar members areangularly moved relative to said drive members upon engagement with thebag material, and second springs urging the strippers to a predeterminedposition from what they are angularly moved relative to the drivemembers upon engagement with the bag material.

[0018] Preferably, said machine includes a mounting member fixed tooeach drive member, with the stripper brackets and deflector bracketsbeing pivotally attached to a respective one of the mounting members.

[0019] Preferably, one of the bar members is provided with alongitudinally standing projection and the other bar member with alongitudinally extending recess within which the projection is receivedwith the bag material so as to be deflected thereby.

[0020] Preferably, one of the bar members including a longitudinallyextending recess and the other bar member a longitudinally extendingprojection to be received in said recess with said bag material so thatsaid bag material is laterally deflected at three locations spaced alongthe bag material.

[0021] In an alternative configuration one of the bar members is locatedupstream along the bag material relative to the other bar member.

[0022] In an alternative configuration the deflecting and closingmembers include a pair of closing members which engage the tubular bagmaterial to close the tubular bag material, and a deflecting member thatengages the tubular bag material downstream of the closing members,which deflecting member laterally deflects the tubular bag material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1 is a schematic side elevation of a packaging machine;

[0024]FIG. 2 is a schematic side elevation of a modification of thepackaging machine of FIG. 1,

[0025]FIG. 3 is a schematic side elevation of a further modification ofthe packaging machine of FIG. 1;

[0026]FIG. 4 is a schematic side elevation of a still furthermodification of the packaging machine of FIG. 1;

[0027]FIG. 5 is a schematic side elevation of a pair of co-operatingdeflection members employed in the packaging machine of FIG. 1;

[0028]FIG. 6 is a schematic front elevation of an assembly includingdeflection members and stripper members of the packaging machine of FIG.1;

[0029]FIG. 7 is a schematic end elevation of the assembly of FIG. 6;

[0030]FIG. 8 is a schematic front elevation of one of the deflectionmembers of FIG. 5;

[0031]FIG. 9 is a schematic end elevation of the deflection member ofFIG. 8;

[0032]FIG. 10 is a schematic front elevation of the other deflectionmember of FIG. 5; and

[0033]FIG. 11 is a schematic end elevation of the deflection member ofFIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] In FIGS. 1 and 5 to 11 of the accompanying drawings there isschematically depicted a packaging machine 10. The machine 10 is arotary packaging machine to which there is delivered tubular bagmaterial 36 within which product is located. The machine 10 formstransverse seals in the tubular bag material 36 and transversely cutsthe tubular bag material 36 to form discrete bags 37.

[0035] The transverse seals are formed and the tubular bag material 36cut by sealing heads 11 and 12 which are mounted on arms (drivermembers) 13 and 14. That is the heads 11 and 12 have a knife blade. Thearms 13 and 14 extend radially from shafts 15 and 16, which shafts 15and 16 are rotatably driven through repeated revolutions in synchronismin opposite rotational directions about spaced parallel generallyhorizontal axes. The shafts 15 and 16 have generally horizontal,parallel and transversely spaced longitudinal axes. In this embodiment,the axes are substantially stationary except for movement required forthe purposes of ensuring correct contact between the sealing heads 11and 12 However, one or both of the shafts 15 and 16 may be mounted forlimited horizontal and/or limited vertical movement if so required.

[0036] Also mounted on arms 13 and 14 are stripper bars 17 and 18respectively, each extending between a pair of support brackets 19. Eachbracket 19 is pivotally supported by means of a shaft 20 on a support(mounting) member 21. Each support member 21 in turn being mounted onits associated arm 13, 14 so as to be fixed with respect thereto,

[0037] Extending between each bracket 19 and the member 21 is a spring22 urging the associated bracket 19 to engage a stop 23. The stops 23define the rest positions of the stripper bars 17 and 18. Each stripperbar 17 and 18 includes an arcuate bag shield 24 and projections 25between which bag “deflator” springs 26 extend.

[0038] Also mounted on the support member 21 is a pair of supportbrackets 27 between which there extends tubular bag deflecting memberswhich in this embodiment are in the form of tube closer bars 28 and 29.Extending between each bracket 27 and the member 21 is a spring 30 whichpasses round a pulley 31 to be secured at location 32 on the is member21. Each support 21 is urged by the spring 30 to engage a stop 33.Accordingly, the stops 33 define rest positions for the closer bats 28and 29.

[0039] In this embodiment the closer bar 28 has a longitudinallyextending projection 34 that engages within a longitudinally extendingrecess 35 of the bar 29.

[0040] When the projection 34 enters the recess 35, together with thetubular bag material 36, the tubular bag material 36 is caused to followa tortuous path, that is it is first deflected in a direction transverseof the normal direction of travel of the tubular bag material 36, andthen is subsequently deflected in the reverse direction. That is the bagmaterial 36 is deflected at three longitudinally spaced locations 52.

[0041] The brackets 27 are each pivotally supported by means of a shaft38 on the associated support member 21.

[0042] As the support members 21 are attached to and rotate with thearms 13 and 14, the bars 28 and 29 not only move angularly with theheads 11 and 12, but can also angularly movable relative to the heads 11and 12 as a result of the brackets 27 being pivotally mounted on thesupport members 21.

[0043] In respect of the above preferred embodiment it should beappreciated that the sealing heads 11 and 12 are essentially fixedrelative to their associated arms 13 and 14. There is some limitedmovement to facilitate seating. However, the above-described arrangementis also applicable to “flat jaw” rotary machines, that is, arrangementsin which the heads 11 and 12 follow arcuate pats but are connected byrods so that their orientation does not change during their cycle.

[0044] In the above-described preferred embodiment the bars 28 and 29rotate in unison in opposite directions through repeated revaluations,as a result of being mounted on arms 13 and 14, so that they are alignedtransversely of the tubular bag material 36 when engaging therewith.However, in an alternative embodiment tube closer bars 28 and 29 may beemployed (not necessarily having the recess 35 and projection 34) whichare not aligned, that is, the bar 28 for example could be angularlyahead of the bar 29 so that they are no longer transversely aligned whenengaged with the bag material 36. In such an to arrangement the tubularbag material 36 is again deflected in a first direction transverse ofthe normal direction of travel of the tubular bag material 36 and thendeflected in the reverse direction.

[0045] In the above-described preferred embodiment the stripper bars 17and 18 advance down the tubular bag material 36 to perform a “stripping”function. That is the bars 17 and 18 advance down the tubular bagmaterial 36 to reduce the volume occupied by the product being packaged.Thereafter, the heads 11 and 12 engage the tubular bag material 36 tofort the transverse seal and to cut the bag 37 from the tubular bagmaterial 36. As can be noted from FIG. 1 the bag deflecting members,that is, tube closer bars 28 and 29, are located immediately above theheads 11 and 12 and prevent product delivered to the interior of thetubular bag material 36 from falling to a position at which the productis located between the heads 11 and 12. As can be seen from FIG. 1 theheads 11 and 12 have corrugated faces. These faces advance the tubularbag material 36, but not to the extent where product, such as crumbs, ispulled past the bars 28 and 29 and allowed to fall to a position betweenthe heads 11 and 12. Thus the bars 28 and 29 provide deflecting andclosing members.

[0046] In the embodiment of FIG. 2 the bars 28 and 29 are of a differentconfiguration. in this embodiment the bars 28 and 29 includelongitudinally extending projections 41 and 42 that are not transverselyaligned as in the case of the projection 34 and recess 35. Moreparticularly, the projection 42 is located downstream, of the tubularbag material 36, relative to the projection 41. The projection 41deflects the tubular bag material 36 transversely to the normaldirection of travel of the tubular bag material 36 and the projection 42deflects the tubular bag material 36 in the opposite direction. In thisrespect it should be appreciated that the projections 41 and 42 also actto close the tubular bag material 36 as well as deflect it. Accordingly,in this embodiment the projections 41 and 42 provide deflecting andclosing members.

[0047] If so required, a still further deflecting member 43 can be used.The deflecting member 43 is mounted directly on the arm 13 so as torotate therewith. The member 43 engages the tubular bag material 36 inbetween the deflecting members 41 and 42 and the heads 11 and 12. Inthis respect it should be appreciated that the member 43 is fixedrelative to the heads 11 and 12 while the projections 41 and 42 moverelative to the heads 11 and 12, when the projections 41 and 42 areengaged with the tubular bag material 36.

[0048] The projections 41 and 42, as discussed above, also act as tubecloser bars. They to are mounted in a similar manner to the bars 28 and29.

[0049] In the embodiment of FIG. 3, the tube closer bars 28 and 29 areeach provided with a “C” shaped engagement member 44 or 45, so that eachengagement member 44, 45 has a recess 46. Projecting into each recess 46is a portion of the other engagement member 44, 45. Accordingly, themembers 44 and 45 are not transversely aligned relative 15 to thetubular bag material 36, that is, the engagement member 45 is locatedcloser to the heads 11 and 12 than the engagement member 44. Theengagement member acts as bag material deflecting and closing member.

[0050] As discussed earlier, if desirable, a further deflection member43 could be used.

[0051] In the embodiment of FIG. 4, the tube closer bars 28 and 29 areof a circular transverse cross section so as Rot to have any projectionsor recesses. However, deflection of the tubular bag material 36 isperformed by the member 43, as discussed previously.

[0052] In an alternative arrangement, as shown in FIG. 4, a single bagdeflection member 43 may be employed with tube closer bars 28 and 29(not necessarily having the projection 34 and recess 35). The bagdeflection member 43 being mounted with one of the heads 11 or 12 so asto rotate therewith, but engage the bag material 36 to cause deflectionthereof. Accordingly, the bag material deflecting and closing membersare provided by the bars 28 and 29, and the member 43. It should benoted that the bars 28 and 29, while being mounted on the supports 21,move angularly relative to the heads 11 and 12 when the bars 28 and 29are engaged.

[0053] In the above-described preferred embodiments the tubular bagmaterial 36 is deflected from its normal direction of travel by one ormore bag material deflecting members. In a number of embodiments the bagmaterial deflecting members are tube close bars 28 and 29 while inanother embodiment a bag material deflecting member 43 is employed witha pair of tube closer bars 28 and 29. By deflecting the tubular bagmaterial 36 as discussed above, product (particularly crumbs) isinhibited from being located between the sealing heads 11 and 12.Tubular bag material 36 that is advanced relative to the bag materialdeflecting members, for example the bars 28 and 29, is not advanced tothe extend that crumbs will pass the bars 28 and 29 and enter the areabetween the heads 11 and 12. As the deflecting members rotate with thejaws 11 and 12, the deflecting members move between being spaced fromthe bag material 36 allowing product to pass along the bag material 36,and being engaged with the bag material 36 to at least substantiallyprevent material being located between the sealing jaws 11 and 12. Thuseach of the above embodiments includes an assembly 50 which in a firstoperative configuration allows product to pass along the bag material36, while in a second operative configuration at least substantiallyprevents product passing along the bag material past the deflectingmembers and being located between the jaws 11 and 12.

The claims defining the invention are as follows:
 1. A rotary packagingmachine including: a pair of rotatably driven jaws to engage tubular bagmaterial passing through the machine in a general direction of travel,the jaws being adapted to form transverse seals in s the bag material toform discrete bags containing product; a drive member supporting eachjaw, the drive members being driven in synchronism in oppositerotational directions; and an assembly to at least substantially preventproduct being located between the jaws during sealing engagement withthe tubular bag material, said assembly having a first operativeconfiguration allowing product to pass along the bag material and asecond operative configuration, said assembly when in said secondconfiguration being engaged with the bag material to at leastsubstantially prevent product being located between the jaws duringsealing, said assembly including bag material deflecting and closingmembers mounted on said drive member so as to rotate therewith, whichdeflecting and closing members close said bag material and deflect saidbag material laterally relative to said direction to at leastsubstantially prevent product being located between the jaws whenforming said seals.
 2. The machine of claim 1 wherein said deflectingand closing members include: a pair of bar members which deflect andclose said tubular bag material, a deflector bracket for each barmember, each bracket mounting the associated one of the bar members on arespective one of the drive members, and wherein the brackets providefor relative movement between each bar member and the jaw of therespective drive member so that each bar member moves relative to itsassociated jaw when the bar member is engaged with the tubular bagmaterial.
 3. The machine of claim 1 wherein the bar members deflect thetubular bag material laterally in one direction and laterally in theopposite direction to said one direction.
 4. The machine of claim 2wherein the bar members are configured to also close the bag material;and said machine further includes strippers that engage the bag materialdownstream of the bar members in said direction to strip the bagmaterial prior to sealing, said strippers being mounted on the drivemembers so that each drive member has mounted on it one of the barmembers and one of the strippers.
 5. The machine of claim 4 wherein eachdetector bracket is pivotally mounted on its respective drive member sothat the bar members move angularly relative to the respective one ofthe drive members, and said machine further includes a pair of stripperbrackets that support the strippers, each stripper bracket beingplurality mounted on a respective one of the drive members so that thestrippers move angularly relative to their respective drive members. 6.The machine of claim 5 wherein the machine further includes firstsprings urging the bar members to a predetermined position from whichthe bar members are angularly moved relative to said drive members uponengagement with the bag material, and second springs urging thestrippers to a predetermined position from what they are angularly movedrelative to the drive members upon engagement with the bag material. 7.The machine of claim 6 wherein said machine includes a mounting memberfixed too each drive member, with the stripper brackets and deflectorbrackets being pivotally attached to a respective one of the mountingmembers.
 8. The machine of claim 7 wherein one of the bar members isprovided with a longitudinally standing projection and the other barmember with a longitudinally extending recess within which theprojection is received with the bag material so as to be deflectedthereby.
 9. The machine of claim 3 wherein one of the bar membersincluding a longitudinally extending recess and the other bar member alongitudinally extending projection received in said recess with saidbag material so that said bag material is laterally deflected at threelocations spaced along the bag material.
 10. The machine of claim 3wherein one of the bar members is located upstream along the bagmaterial relative to the other bar member.
 11. The machine of claim 1wherein the deflecting and closing members include a pair of closingmembers which engage the tubular bag material to close the tubular bagmaterial, and a deflecting member that engages the tubular bag materialdownstream of the closing members, which deflecting member laterallydeflects the tubular bag material.
 12. The machine of claim 1 whereinthe deflecting and closing members arc a pair of bar members, each barmember being pivotally mounted on a reflective one of the drive members,one of said bar members having a longitudinally extending recess and theother bar member having a longitudinally extending projection receivedwithin the recess with the bag material to cause deflection and closingthereof.
 13. The machine of claim 12 further including stripperspivotally mounted on the drive member that engage its bag material downstream in said direction from said bar members.